Neutral bar assembly

ABSTRACT

A system of components which can be grouped into sets for assembly in various configurations to provide electrical neutral bar assemblies of different shapes and having different numbers of neutral-wire-receiving openings. The system, which is particularly suitable for use with neutral wires of relatively large ampacity, includes a plurality of insulating bases, a plurality of neutral bars of different lengths, and an interconnecting plate. One or more of the bases and one or more of the neutral bars with or without the interconnecting plate are arranged to be secured together in different configurations by bolts.

United States Patent [72] Inventor Harris 1. Stanback Lexington, Ky. [211 App]. No 6,172 (22] Filed Jan. 27, 1970 [45] Patented July 20, 1971 [73] Assignee Square D Company Park Ridge, [IL

{54] NEUTRAL BAR ASSEMBLY 11 Claims, 6 Drawing Figs.

[52] US. Cl 339/198, 317/1 18, 339/19, 339/242 [51] Int. Cl ll-llOlr 9/00 [50] Field ofSearch 339/198, 198.6, 1980; 174/72;317/118 [56] References Cited UNITED STATES PATENTS 2,831,071 4/1958 Taylor 339/22 X 2,909,757 10/1959 Speck 339/l98(.6) FOREIGN PATENTS 41 1,075 10/1966 Switzerland 339/242 Primary Examinep-Stephen J. Novosad Assistant Examiner-Robert A. Hafer Attorneys-Harold J. Rathbun and Paul J. Rose ABSTRACT: A system of components which can be grouped into sets for assembly in various configurations to provide electrical neutral bar assemblies of different shapes and having different numbers of neutral-wire-receiving openings. The system, which is particularly suitable for use with neutral wires of relatively large ampacity, includes a plurality of insulating bases, a plurality of neutral bars of different lengths, and an interconnecting plate. One or more of the bases and one or more of the neutral bars with or without the interconnecting plate are arranged to be secured together in different configurations by bolts.

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sum 2 or 2 INVENTOR. HARRIS 1. STANBACK FIG. 6

NEUTRAL BAR ASSEMBLY This invention relates to an improved system of neutral bar components from which sets of the components may be selected to form various neutral bar assemblies for use with neutral conductors of relatively large ampacity.

In the manufacture of electrical switching devices of various complexities it is necessary to provide neutral bar assemblies capable of receiving various numbers of neutral conductors. For switching devices of relatively small ampacity, different neutral bar assemblies can be constructed by providing relatively long neutral bars which can be readily cut into various lengths with one or more of the shorter neutral bars mounted on a supporting bracket. HOwever, when the neutral bars must be capable of accommodating neutral conductors of large size and it is desired to have neutral-wire-receiving openings in the end faces of the bars, the desired flexibility in the creation of different assemblies has not heretofore been obtained.

An object of the invention is to provide an improved system of components capable of being grouped to form various sets of neutral bar components with each set of components being useable to construct a neutral bar assembly of a desired configuration and having a predetermined number of neutralwire-receiving openings.

Another object is to provide an improved neutral bar assembly comprising at least two neutral bars stacked upon each other and upon a base member and held together by bolts.

A further object is to provide an improved neutral bar as sembly comprising a plurality of neutral bars stacked upon each other in at least two side-by-side tiers which are electrically interconnected by a plate member common to all of the tiers.

A further object is to provide an improved neutral bar assembly comprising a plurality of neutral bars each having wire-receiving openings in their opposite end faces and with accessibility to all connections provided even when the neutral bars are stacked one upon another.

OTher objects of this invention will become apparent from the following specification wherein reference is made to the drawings, in which:

FIG. 1 is a perspective view of one configuration of a neutral bar assembly incorporating components of the neutral bar system of this invention;

FIG. 2 is an end view of the neutral bar assembly of FIG. 1 taken generally from the left thereof;

FIG. 3 is a sectional view taken generally along the line 3-3 of FIG. 2;

FIG. 4 is a perspective view of another configuration of a neutral bar assembly incorporating components of the neutral bar assembly incorporating components of the neutral bar system of this invention;

FIG. 5 is an end view of the neutral assembly of FIG. 4 taken generally from the left thereof; and

FIG. 6 is a sectional view taken generally along the line 6-6 of FIG. 5.

The neutral bar assembly incorporating components of the neutral bar system of this invention shown at 10 in FIGS. 1, 2 and 3, comprises a relatively long neutral bar 12, a relatively short neutral bar 14, and an insulating base 16 stacked in building block fashion to form a single tier secured together by securing means in a manner to be described. The assembly 10 is shown as fastened to a base plate 18, representative of a wall of an enclosure of an electrical switching device, by two bolts 20 extending through openings 22 located respectively in foot portions 16a at opposite end portions of the base l6. The base 16 may also have a central foot portion 16b.

The neutral bars 12 and 14 are preferably square in transverse cross section and tubular having longitudinal wirereceiving opening 24 and 26, respectively. THe openings 24 and 26 are preferably circular and are eccentric with respect to the longitudinal axes of the respective neutral bars I2 and 14 so that an upper wall 120 of the bar 12 is thicker than a lower wall 12b and an upper wall 14a of the bar 14 is thicker than a lower wall 14b. Neutral wires or cables (not shown) may be inserted into respective end portions of the openings 24 and 26 and securely held in position and in electrically conductive relation to the neutral bars by wire-clamping binding screws 28a-28b and Mia-30b, respectively the binding screws 28a and 28b being threaded into respective openings extending through opposite end portions of the upper Wall 120 of the neutral bar 12 and the screws 30a and 30b being similarly threaded into respective openings extending through opposite end portions of the upper wall 14a of the neutral bar 14.

An aligned pair of access openings 32a and an aligned pair of access openings 32b are provided in the walls 12a and 12b of the long bar 12 to provide access by a tool to the binding screws 30a and 30b in the bar 14 so that neutral wires inserted into the respective end portions of the wire-receiving openings 26 in the bar 14 can be clamped or unclamped without prior removal of the bar 12. It is thus apparent that stacking of the long neutral bar 12 on top of the short neutral bar 14 provides for ease of access to both sets of binding screws 28a -28b and 30a -30b without interference from neutral wires (not shown) inserted in the respective openings 24 and 26.

As shown best in FIG. 3, the neutral bars 12 and 14 are secured to the base 16 and to each other by a bolt 34 which passes through a bolt-receiving opening 35 in the base 16 and aligned pairs of bolt-receiving openings 360-36b and 3&1-38/2 in the bars 14 and 12, respectively, the bolt and openings thus constituting a securing means. The bolt-receiving opening 36b is in the lower wall 14b of the bar 14 and is threaded to accept a complementary threaded portion 40 of the bolt 34. This threaded coupling secures the short bar 14 to the base 16. The long bar 12 is secured firmly in position by a hexagonal nut 42 threaded on an upper threaded portion 44 of the bolt 34.

Additional securing means for the bars 12 and 14 and the base 16 comprise a bolt 46 which is received through an opening 47 in the base 16, an aligned pair of bolt-receiving openings 48a -48b in the bar 14, and an aligned bolt-receiving opening 50 in the bar 12. The opening 50 is in the lower wall 12b of bar 12 and is threaded to engagea threaded portion 52 of the bolt 46. The bolts 34 and 46 thus locate the bars 12 and 14 in fixed position with respect to each other and to the base 16 and secure the components firmly in assembled relation with good electrical 5 conductivity between the bars 12 and 14. The completed assembly 10 can then be attached to the base plate 18 as previously described. It should be noted that the foot portion 16b provides additional insulation between the heads of the bolts 34 and 46.

A box-type terminal lug 54 may be secured to the outer surface of the upper wall 120 of the bar 12 by a screw 56 threaded into an opening 58 in the wall 12a. The lug 54 has a wire-receiving opening 60 for receiving a ground or other wire (not shown) which may be held securely in position by means of a binding screw 62 threaded into an opening in the upper wall of the lug 54. A opening 63 in the upper wall 12a of the bar 12 is provided for securing a self-tapping screw which may be used to secure a bonding wire (not shown) to the assembly when such is required.

FIGS. 4, 5, and 6 illustrate another neutral bar assembly incorporating a set of components of the neutral bar system of this invention. The assembly of FIGS. 4, 5, and 6 has provision for an increased number of neutral conductors. In this second embodiment, additional components identical with those of the assembly 10 of FIGS. 1, 2, and 3 are identified by the same reference characters plus 1100. In the second embodiment, insulating bases 16 and 116 are secured in side-by-side relation to one another on the base plate 18. Stacked in overlying relation on both of the bases 16 and 116 is a conductive connecting plate 64. On the plate 64 at one side edge portion thereof is one of the short neutral bars 14, and a relatively long neutral bar 12 is positioned on top of the short neutral bar I4. On the connecting plate at the other side edge thereof is along neutral bar I12.

The portion of the assembly 100 to the left of the plane defined by the abutting walls of the short neutral bar I4 and the long neutral bar 112 is similar to the assembly shown in FIGS 1, 2, and 3. Although the connecting plate 64 is inter posed between the base 16 and the short bar 14, the bars 12 and 14 of the assembly of FIGS. 4, 5, and 6 ar secured together in the same manner as that previously described except that the bolts 34 and 46 are longer to accommodate the plate 64.

Referring to FIG. 6, a bolt 66 received through an opening 135 in the base 116 passes through an opening 68a in the connecting plate 64 and an aligned pair of openings 138a and 138b in the neutral bar 112, and a hexagonal nut 70 is threaded on an upper portion 72 of the bolt 66. An additional securing means for the bar 112 comprises a bolt 74 received through an opening 147 in the base 116, an opening 68b in the plate 64, and an opening 150 in the lower wall ll2b of the neutral bar 112. The opening 150 is threaded and engages a threaded end portion 76 of the bolt 74. Thus the bolts 66 and 74 and the associated openings locate the bar 112 and the plate 64 in fixed position with respect to the base 116 and secure the components firmly in fixed relation.

A box-type terminal lug 154 may be secured to the outer surface of the top wall 11211 of the bar 112 by a screw 156 which is threaded into an opening 158 in the wall 11211. The lug 54 has a wire-receiving opening 160 for receiving a ground or other wire (not shown) which may be held securely in position by means ofa binding screw 162 which is threaded into an opening in the upper wall ofthe lug 154.

After assembly, the neutral bar assembly 100 can be attached to the base plate 18 by means of screws and 120 inserted respectively through openings 22 and 122 located respectively in opposite end portions of the bases 16 and 116.

It should be noted that the spatial relationship of the components is determined by openings (not shown) in the plate 64 which bear the same relationship to the bars 12 and 14, plate 64, and the base 16 as do the openings 68a and 68b to the bar 112. Thus the plate 64 serves to maintain the spatial relationship of the components of the assembly 100 and serves to insure good electrical conductivity between the two tiers.

Although only two configurations of neutral bar assemblies are illustrated in the drawings, it is obvious that others can be constructed using different sets of the components of the im proved system. The two configurations shown are particularly suitable for use in a narrow wiring channel at the side of a switch mounted in an enclosure into which relatively stiff large wires enter through knockouts in the top or bottom walls of the enclosure.

lclaim:

1. A system of neutral bar assembly components capable of being grouped in various quantities into sets for construction of neutral bar assemblies of various configurations, said components comprising a plurality of identical relatively short neutral bars, a plurality of identical relatively long neutral bars, a conductive plate upon which the neutral bars may be mounted in side-by-side relation, and a plurality of insulating bases, securing means for securing the plate on a pair of the bases, securing the short neutral bars either singly directly on a base or in side-by-sidc relation directly on the plate, and for securing the long neutral bars either singly directly on a base, in side-by-side relation directly on the plate, or in stacked relation respectively on the short neutral bars, each of the neutral bars having wire-receiving openings in its end walls, respectively, and each having screw-receiving openings in its top wall intersecting the respective wire-receiving openings, screw threaded into the screw-receiving openings, respectively, and access openings extending through each of the long neutral bars positioned so as to be in alignment respectively with the screw-receiving openings of the relatively short neutral bars when any one of the long neutral bars is secured by the securing means in stacked relation on any one of the short neutral bars thereby to expose the screws for access by a tool.

2. A neutral bar assembly comprising an insulating base, a relatively short neutral bar of rectangular cross section mounted on the base, a relatively long neutral bar of rectangular cross section mounted on the short neutral bar, securing means securing the base and the neutral bars together in fixed relation, each of the neutral bars having wire-receiving openings in its opposite end walls, respectively, and each having screw-receiving openings in its upper wall intersecting the wire receiving openings, access openings extending through the long neutral bar and positioned in vertical alignment with the respective wire-clamping screws of the relatively short neutral bar, when the bars are secured in said fixed relation by the securing means, thereby to expose the screws for access by a tool.

3. A neutral bar assembly as in claim 2 wherein each of the neutral bars is tubular having a longitudinal opening and wherein opposite end portions of the longitudinal opening respectively define the wire-receiving openings.

4. A neutral bar assembly as in claim 2 wherein the securing means includes a tapped opening in one of the neutral bars and a bolt having a threaded portion received in said tapped opening.

5. A neutral bar assembly as in claim 2 wherein the securing means includes a pair of longitudinally spaced transverse openings extending through the relatively short neutral bar from the bottom wall to the top wall thereof, and a pair of longitudinally spaced transverse openings in the relatively long neutral bar one of which extends inwardly of the bar from the bottom wall and the other of which extends through the bar from the bottom wall to the top wall thereof, the transverse openings of the relatively short neutral bar being spaced the same distance apart as the transverse openings of the relatively long neutral bar.

6. A neutral bar assembly as in claim 5 wherein one of the transverse openings in the relatively short neutral bar and said one transverse opening in the relatively long neutral bar are threaded only at the respective portions thereof near the lower walls of the respective bars.

7. A neutral bar assembly as in claim 5 wherein each of the longitudinally spaced transverse openings in the bars is equally spaced from a transverse centerline of its respective bar.

8. A neutral bar assembly as in claim 2 wherein the securing means comprises transverse bolt-receiving openings in the base and bars, respectively, which are aligned when the base and bars are positioned to be secured in said fixed position, and a bolt received in the aligned openings with a lower threaded portion of the bolt threaded into the opening in the relatively short neutral bar.

9. A neutral bar assembly as claimed in claim 8 wherein the securing means comprises transverse bolt-receiving openings in the base and bars, respectively, which are aligned when the base and bars are positioned to be secured in said fixed position, and a bolt received in the aligned openings with an upper threaded portion of the bolt threaded into the opening in the relatively long neutral bar.

10. A neutral bar assembly as in claim 2 wherein the securing means comprises first transverse bolt-receiving openings in the base and bars, respectively, which are aligned with each other when the base and bars are positioned to be secured in said fixed relation, 2 first bolt received in the first aligned boltreceiving openings with a lower threaded portion threaded into the first bolt-receiving opening in the relatively short neutral bar, second transverse bolt-receiving openings in the base and bars, respectively, longitudinally spaced from the first bolt-receiving openings, and aligned with each other when the base and bars are positioned to be secured in said fixed relation, and a second bolt received in said second boltreceiving openings with an upper threaded portion of the bolt threaded into the second bolt-receiving opening in the relatively long neutral bar.

II. A neutral-bar assembly comprising an insulating base means, a conductive plate mounted on the base means, two lower neutral v bars of rectangular cross section mounted in threaded respectively into the screw-receiving openings, access openings extending through the relatively long neutral bar positioned in alignment respectively with the screws ofthe relatively short neutral bar on which it is mounted, and to which it is secured in said fixed relation, thereby to expose the screws for access by a tool. 

1. A system of neutral bar assembly components capable of being grouped in various quantities into sets for construction of neutral bar assemblies of various configurations, said components comprising a plurality of identical relatively short neutral bars, a plurality of identical relatively long neutral bars, a conductive plate upon which the neutral bars may be mounted in side-by-side relation, and a plurality of insulating bases, securing means for securing the plate on a pair of the bases, securing the short neutral bars either singly directly on a base or in side-by-side relation directly on the plate, and for securing the long neutral bars either singly directly on a base, in side-by-side relation directly on the plate, or in stacked relation respectively on the short neutral bars, each of the neutral bars having wire-receiving openings in its end walls, respectively, and each having screw-receiving openings in its top wall intersecting the respective wire-receiving openings, screw threaded into the screw-receiving openings, respectively, and access openings extending through each of the long neutral bars positioned so as to be in alignment respectively with the screwreceiving openings of the relatively short neutral bars when any one of the long neutral bars is secured by the securing means in stacked relation on any one of the short neutral bars thereby to expose the screws for access by a tool.
 2. A neutral bar assembly comprising an insulating base, a relatively short neutral bar of rectangular cross section mounted on the base, a relatively long neutral bar of rectangular cross section mounted on the short neutral bar, securing means securing the base and the neutral bars together in fixed relation, each of the neutral bars having wire-receiving openings in its opposite end walls, respectively, and each having screw-receiving openings in its upper wall intersecting the wire-receiving openings, access openings extending through the long neutral bar and positioned in vertical alignment with the respective wire-clamping screws of the relatively short neutral bar, when the bars are secured in said fixed relation by the securing means, thereby to expose the screws for access by a tool.
 3. A neutral bar assembly as in claim 2 wherein each of the neutral bars is tubular having a longitudinal opening and wherein opposite end portions of the longitudinal opening respectively define the wire-receiving openings.
 4. A neutral bar assembly as in claim 2 wherein the securing means includes a tapped opening in one of the neutral bars and a bolt having a threaded portion received in said tapped opening.
 5. A neutral bar assembly as in claim 2 wherein the securing means includes a pair of longitudinally spaced transverse openings extending through the relatively short neutral bar from the bottom wall to the top wall thereof, and a pair of longitudinally spaced transverse openings in the relatively long neutral bar one of which extends inwardly of the bar from the bottom wall and the other of which extends through the bar from the bottom wall to the top wall thereof, the transverse openings of the relatively short neutral bar being spaced the same distance apart as the transverse openings of the relatively long neutral bar.
 6. A neutral bar assembly as in claim 5 wherein one of the transverse openings in the relatively short neutral bar and said one transverse opening in the relatively long neutral bar are threaded only at the respective portions thereof near the lower walls of the respective bars.
 7. A neutral bar assembly as in claim 5 whereIn each of the longitudinally spaced transverse openings in the bars is equally spaced from a transverse centerline of its respective bar.
 8. A neutral bar assembly as in claim 2 wherein the securing means comprises transverse bolt-receiving openings in the base and bars, respectively, which are aligned when the base and bars are positioned to be secured in said fixed position, and a bolt received in the aligned openings with a lower threaded portion of the bolt threaded into the opening in the relatively short neutral bar.
 9. A neutral bar assembly as claimed in claim 8 wherein the securing means comprises transverse bolt-receiving openings in the base and bars, respectively, which are aligned when the base and bars are positioned to be secured in said fixed position, and a bolt received in the aligned openings with an upper threaded portion of the bolt threaded into the opening in the relatively long neutral bar.
 10. A neutral bar assembly as in claim 2 wherein the securing means comprises first transverse bolt-receiving openings in the base and bars, respectively, which are aligned with each other when the base and bars are positioned to be secured in said fixed relation, a first bolt received in the first aligned bolt-receiving openings with a lower threaded portion threaded into the first bolt-receiving opening in the relatively short neutral bar, second transverse bolt-receiving openings in the base and bars, respectively, longitudinally spaced from the first bolt-receiving openings, and aligned with each other when the base and bars are positioned to be secured in said fixed relation, and a second bolt received in said second bolt-receiving openings with an upper threaded portion of the bolt threaded into the second bolt-receiving opening in the relatively long neutral bar.
 11. A neutral bar assembly comprising an insulating base means, a conductive plate mounted on the base means, two lower neutral bars of rectangular cross section mounted in side-by-side relation on the plate, at least one of the lower neutral bars being relatively short, a relatively long upper neutral bar mounted on the relatively short neutral bar, securing means securing the base means, plate and neutral bars together in fixed relation, each of the neutral bars having wire-receiving openings in its opposite end walls, respectively, and each having screw-receiving openings in its upper wall intersecting the cable-receiving openings, respectively, screws threaded respectively into the screw-receiving openings, access openings extending through the relatively long neutral bar positioned in alignment respectively with the screws of the relatively short neutral bar on which it is mounted, and to which it is secured in said fixed relation, thereby to expose the screws for access by a tool. 